Light emitting device, method of manufacturing the same, light emitting device package, and lighting system

Abstract

Disclosed is a light emitting device. The light emitting device includes a light emitting structure layer including a first conductive type semiconductor layer, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer, a first light extracting structure formed on an outer portion of the first conductive type semiconductor layer and having a plurality of side surfaces and a plurality of upper surfaces formed in a step structure, and a transmissive layer on the first light extracting structure of the first conductive type semiconductor layer.

What is claimed is: 
     
       1. A light emitting device comprising:
 a light emitting structure layer including a first conductive type semiconductor layer, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer; 
 a first light extracting structure disposed on an outer side of the first conductive type semiconductor layer and including a plurality of side surfaces and a plurality of upper surfaces formed in a step structure; 
 a transmissive layer on the first light extracting structure of the first conductive type semiconductor layer; 
 a first semiconductor layer under the first conductive type semiconductor layer; and 
 a second light extracting structure which is disposed on an outer portion of the first semiconductor layer and includes a plurality of side surfaces and a plurality of upper surfaces formed in a step structure. 
 
     
     
       2. The light emitting device of  claim 1 , wherein the transmissive layer further extends on the second light extracting structure of the first semiconductor layer. 
     
     
       3. The light emitting device of  claim 1 , wherein the transmissive layer has a thickness thinner than a thickness of the first conductive type semiconductor layer. 
     
     
       4. The light emitting device of  claim 1 , wherein the transmissive layer includes a rough layer on the outer side of the first conductive type semiconductor layer and an outer surface of the rough layer has a roughness. 
     
     
       5. The light emitting device of  claim 1 , wherein the upper surface of the first light extracting structure is a Ga-face. 
     
     
       6. The light emitting device of  claim 1 , wherein the first conductive type semiconductor layer has a width which is gradually widened as the first conductive type semiconductor layer is farther away from the active layer. 
     
     
       7. The light emitting device of  claim 1 , wherein the outer portion of the first conductive type semiconductor layer and the first light extracting structure are inclined with respect to a lower surface of the first conductive type semiconductor layer. 
     
     
       8. The light emitting device of  claim 1 , wherein the transmissive layer includes conductive material or insulating material. 
     
     
       9. The light emitting device of  claim 1 , wherein the transmissive layer has a refractive index lower than a refractive index of the first conductive type semiconductor layer. 
     
     
       10. The light emitting device of  claim 1 , wherein each upper surface of the first light extracting structure is formed in a loop shape along an outer peripheral portion of the first conductive type semiconductor layer. 
     
     
       11. The light emitting device of  claim 1 , further comprising a electrode contact portion formed in a step structure on at least one outer portion of the first conductive type semiconductor layer and spaced apart from a side surface of the active layer; and a first electrode disposed on the upper surface of the electrode contact portion. 
     
     
       12. A light emitting device comprising:
 a substrate; 
 a light emitting structure layer including a first conductive type semiconductor layer on the substrate, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer; 
 a first light extracting structure formed at an outer peripheral portion of the first conductive type semiconductor layer and including a plurality of upper surfaces and a plurality of side surfaces formed in a plurality of step structures; and 
 a transmissive layer on the first light extracting structure of the first conductive type semiconductor layer, wherein the upper surfaces provided at the outer peripheral portion of the first conductive type semiconductor layer are Ga-faces, 
 wherein the plurality of upper surfaces include at least three upper surfaces and the plurality of side surfaces include at least three side surfaces. 
 
     
     
       13. The light emitting device of  claim 12 , further comprising a first semiconductor layer on the substrate; and
 a concavo-convex structure including a plurality of convex portions between the substrate and the first semiconductor layer. 
 
     
     
       14. The light emitting device of  claim 13 , wherein outer portions of the first semiconductor layer and the first conductive type semiconductor layer are inclined at a predetermined angle with respect to a lower surface of the substrate,
 wherein the predetermined angle is in a range of about 15° to about 75° with respect to a lower surface of the substrate, and 
 wherein the predetermined angle is an angle between a virtual line linking vertexes of the plurality of step structures and the lower surface of the substrate. 
 
     
     
       15. The light emitting device of  claim 13 , wherein the first semiconductor layer includes at least one of a buffer layer and an undoped semiconductor layer. 
     
     
       16. The light emitting device of  claim 15 , wherein a portion of at least one of the plurality of convex portions is located at an outer position than a side surface of the first semiconductor layer. 
     
     
       17. The light emitting device of  claim 12 , wherein each upper surface of the first light extracting structure is a Ga-face and provided in a loop shape at the outer peripheral portion of the first conductive type semiconductor layer. 
     
     
       18. The light emitting device of  claim 12 , further comprising:
 a first electrode on the first conductive type semiconductor layer; 
 a current spreading layer including transmissive material on the second conductive semiconductor; and 
 a second electrode provided on the current spreading layer. 
 
     
     
       19. The light emitting device of  claim 12 , wherein the transmissive layer includes at least one selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), Al 2 O 3 , Si 3 N 4 , TiO 2 , ZrO 2 , CeF 3 , HfO 2 , MgO, Ta 2 O 5 , ZnS, and PbF 2 . 
     
     
       20. The light emitting device of  claim 12 , wherein the first light extracting structure and the transmissive layer are spaced apart from a side surface of the active layer,
 wherein the transmissive layer includes a rough layer on the outer side of the first conductive type semiconductor layer and an outer surface of the rough layer has a roughness.